Insulated and multi-layered garments are well-known in the art, and are commonly used by people in a variety of activities. For example, insulated garments such as jackets or vests are frequently used by athletes to retain body heat while exercising outdoors, playing in sports, hiking, running, snow skiing, fishing or any of a variety of other outdoor activities that take place in a cold ambient temperature. The purpose of wearing such clothing is to protect the user from loss of core body temperature and to therefore maintain the desired safety and comfort by the user.
These insulated garments are important to keep the individual warm when in a cold environment, in that the garments will conserve an individual's body heat. In particular, approximately ninety percent of the heat of any person's body is produced in the torso area via the major organs and muscle groups, which is conserved by such garments. However, as the individual engages in physical activity or as the ambient temperature increases, the amount of heat generated by the body will also increase. In order to maintain a constant core temperature as desired, the individual's body must either give up or retain this heat as necessary. The reaction of the body is largely dependent on the ambient temperature and humidity surrounding the individual.
It is commonly known that the choice of clothing can help control heat when it comes to physical activity. One of the most common suggestions to athletes and the general public is to wear multiple articles of clothing when exercising or when the temperature is expected to fluctuate significantly. By wearing multiple articles of clothing, the user can remove the outermost articles as necessary to adjust to the ambient temperature. Preferably, the closest layer to the skin would direct sweat away from the skin, and each additional article would trap air that is warmed by the body to help keep the user at a comfortable and desirable temperature.
While layered clothing provides the user with an opportunity to control body heat, this solution raises additional problems. For example, one problem in wearing multiple articles of clothing is that the user often retains too much heat around the core of the body, in which case the user must either remove the unneeded article or articles, or otherwise risk overheating. For the user to be able to remove one layer, either the user has to fasten the garment to another portion of the user's body to reduce the heat surrounding the user's body (such as to tie the garment around the user's waist), or the user must completely discard the garment to be recovered later. In most cases, neither of these options for managing the article of clothing is desirable to the user since they result in a significant inconvenience for the user.
Several garment devices have been developed to answer the problem of body heat control that is experienced by athletic persons and non-athletic persons alike. For example, in U.S. Pat. No. 6,329,638, a design is taught to provide a vest with a heating element to keep the user's body warm as needed. Clearly, this complicated design will overheat the user's body while on, and it is further difficult to cool down once the heating element has been in use. Similarly, U.S. Pat. No. 6,189,149 teaches the use of a vest having pockets in which to insert heat packs. Once again, this design fails to provide a convenient means for heating a person's torso while also providing a means to allow the user to cool down.
What is desired, then, and not found in the prior art, is an apparatus providing an adjustable layer of fabric that may be positioned in an expanded or retracted manner as desired by the user.